Method and device for mold casting utilizing sonic energization



June 3, 1969 A, a. BODINE, JR 3,447,537

METHOD AND DEVICE FOR MQLD CASTING UTILIZING SONIC ENERGIZATION OriginalFiled m 10. 1965 Sheet or s FIG.I

FIG.2

INVENTOR BY ALBERTG. B'JOINE, JR.

SOKOLSKI 8 WOHLGEMUTH NTCRIEYS June 3, 1969 A. G. BODINE, JR

METHOD AND- DEVICE FOR MOLD CASTING UTILIZING SONIC ENERGIZATION SheetOriginal Filed May 10. 1965 FIG.

INVENTOR ALBERT s aounsm. av SOKOLSKI a WOHLGEMUTH ATTORNEYS June 3,1969 METHOD AND DEVICE FOR MOLD CASTING UTILIZING SONIC ENERGIZATIONOriginal Filed May 10. 1965 A. G- YBODINE, JR

Sheet 3 01's INVENTOR. ALBERT G. BOOINE JR.

SOKOLSKI a WOHLGEMUTH ATTORNEYS United States Patent M US. Cl. 164-49 6Claims ABSTRACT OF THE DISCLOSURE Fluid material to be cast is pouredinto a static mold and while it transforms from a fluid to a solid stateis subjected to high-level sonic energy as part of a resonant elasticvibration system. This vibration system is excited by means of anorbiting-mass oscillator which automatcally adjusts its frequency andphase of operation with changes in impedance characteristics of thematerial being cast as it goes from a fluid to a solid state, therebymaintaining optimum resonant operation at all times, such as to improvethe temperature distribution within the large mass of material whilechanging from fluid to solid state.

This application is a division of my application Ser. No. 454,335 filedMay 10, 1965, for Sonic Method and Apparatus for Facilitating GravityFlow of Fluid Material.

Mold casting in which fluid material is poured into a mold and permittedto solidify as it cools to a solidfying temperature is utilizedextensively in forming objects from metal and other materials. Severalproblems are encountered in this type of casting, particularly largeingots, as accomplished under the prior art. Firstly, the casting oftenadheres to the sides of the mold, making removal therefrom difficult.Further, in removal, the surfaces of the casting are oftentimes marred.Additionally, the material being cast often does not conform with theshape of the mold as accurately as would be desired. Moreover, in largeingot castings the center cools last, and thus solidifies last,shrinking and tearing from the outer portion, with resulting flaws.

The technique and device of this invention overcome the shortcomings ofthe prior art by applying high-level sonic energy at the interfacebetween the mold and the static casing and into the casing itself. Suchsonic energization acts to free the sides of the mold from the cast tofacilitate removal from the mold and operates to remove gas and otherimpurities from the cast material as well as to stress-relieve thecasting, and distirbute the temperature while in the plastic state, toimprove its structural characteristics of large ingots.

In carrying out the invention, a resonant elastic vibration system whichincludes the mold itself and in one embodiment includes a dipstickcoupled directly to the casting, is vibrated at a resonant frequency bymeans of an orbiting-mass oscillator. Fluid material is poured into themold and then excited by the resonant vibration as it solidifies. Theorbiting-mass oscillator utilized is adapted to adjust its frequency andphase with changes in the consistency of the casing material as it goesfrom a fluid to a solid state, thereby assuring the maintenance ofoptimum resonant vibration with such changes in the impedance of thecasting.

It is therefore an object of this invention to provide an improvedtechnique for mold casting.

It is a further object of this invention to facilitate the removal of acasting from its mold in a mold casting process.

It is still another object of this invention to improve the 3,447,587Patented June 3, 1969 structural characteristics of castings made bymold casting processes.

It is still a further object of this invention to enable the moreaccurate conformation of castings to their molds in mold castingprocesses.

Other objects of this invention will become apparent as the descriptionproceeds in connection with the accompanying drawings, of which:

FIG. 1 is a cross-sectional view in elevation of a first embodiment ofthe device of the invention;

FIG. 2 is a perspective view of the first embodiment of the device ofthe invention;

FIG. 3 is a cross-sectional view in elevation of a second embodiment ofthe device of the invention;

FIG. 4 is a cross-sectional view in elevation of a third embodiment ofthe device of the invention;

FIG. 5 is a cross-sectional view of an oscillator which may be utilizedin the various embodiments of the device of the invention;

FIG. 6 is a cross-sectional view taken along the plane indicated by 6-6in FIG. 5; and

FIG. 7 is a cross-sectional view taken along the plane indicated by 7--7in FIG. 5.

Referring now to FIGS. 1 and 2, the utilization of the device of theinvention in ingot mold casting is illustrated. Here, molten material 62which may be aluminum to be cast is poured into ingot mold 63. Ingotmold 63 is supported on metallic base plate 64, which in tum issupported on suitable isolation supports 65. Base plate 64 is sonicallyenergized by means of orbiting-mass oscillator 16 which is mountedthereon, which is pneumatically driven by air fed thereto through line19. Oscillator 16 is preferably of the type illustrated in FIGS. 5-7.Orbiting-mass oscillator 16 resonantly vibrates base plate 64 to producestanding waves 67 therein and these vibrations are fed to mold 63 andthe bottom of the molten material 62, and appear at the interfacesbetween the mold and the material 62 being cast. The sonic energy actsto stress-relieve the cast material 62, removes gas and other impuritiestherefrom, provides for more uniform tempera ture, obtains bettercrystal structure, and thus generally improves the characteristics ofthe final end product. The active sonic condition established at theinterfaces between material 62 and the sides of mold 63 prevents thecast material from adhering to the mold, and thus enables easy removaltherefrom when the casting process has been completed. The sonicmechanical oscillator operates at maximum efiiciency by automaticallyadjusting its frequency with changes in the characteristics of the castmaterial as it solidifies.

Referring now to FIG. 2, the utilization of the device of the inventionin a gravity mold in which excitation is provided through a dipstickdirectly to the cast material, is illustrated. Molten material 72 ispoured from hopper 79 into mold 71. Dipstick 74 is suspended in thematerial being cast from resonant bar 76, which is supported by pulleymechanism 78. Orbiting-mass oscillator 16, which is driven pneumaticallythrough line 19, is attached to resonant bar 76 and is oscillated tocause bar 76 to vibrate resonantly with standing waves 80 formedtherealong. The material being cast 72, which may be plastic or a metalsuch as zinc, forms part of the resonantly vibrating system. As alreadymentioned in connection with the other embodiment, orbiting-massoscillator 16 adjusts its frequency as the material being cast hardensand changes in its density and elasticity, so as to maintain optimumresonant vibration throughout the casting process. As explained inconnection with the other embodiment, the sonic energization preventsthe casting from adhering to the mold and imparts superiorcharacteristics to the final end product, removing impurities, gasbubbles, and providing for a better overall structure having greaterdensity, and in the case of metallic castings, superior crystalstructure.

Referring now to FIG. 3, the device of the invention is shown asutilized in conjunction with an injection molding process. Plastic ormolten condition material 96 is injected through mold injector 92, press95 pushing down on the top of mold 94 to hold the mold in place. Sonicenergy is provided to mold 94 from sonic oscillator 16, which ispneumatically driven through line 19. Sonic oscillator 16 is attached toresonant bar 90 to provide high Q resonant vibration, and bar 90 isattached to mold 94 at piston portion 94a thereof. Here again, as in theother casting processes described, the molding process is enhanced bythe resonant sonic vibration to remove impurities and to provide adenser, better formed end product which can readily be removed from themold.

Referring now to FIGS. 5, 6 and 7, a preferred embodiment of thepneumatically driven orbit ing-mass oscillator which may be utilizedwith the device of the invention is illustrated. This orbiting-massoscillator has the unique characteristic of adjusting its frequency ofoperation with load changes, in effect locking in with a resonent loadto maintain such resonant operating condition.

Mounted within case 150 is rotor member 18 which includes a centralcircular portion 151 and an outer circular portion 152 joined togetherby a web portion 153. Extending inwardly from case 150- are a pair ofC-shaped portions 154a and 154b. Pressurized air is fed through inletport 157 to the interior of casing 150. Disc-shaped members 159a and 15%are held between the ends of C-shaped portions 154a and 15%respectively. Disc-shaped members 159a and 15% are held so that they arefree to rotate and to move radially and at the same time provide adivider which prevents any significant amount of the inlet air frompassing directly from one side thereof to the other. An air outlet isprovided from the interior of casing 150 by means of outlet aperture160.

The air entering through inlet 157 enters crescentshaped cavity portions163 and 164 and tangentially drives both inner portion 151 and outerportion 152 of the rotor in a conuterclockwise direction. Suchcounterclockwise rotation of the rotor on its axis results in aclockwise rolling of the rim of outer rotor portion 152 around theraceway formed by the inner wall 168 of casing 150. In view of theeccentricity of the rotor in this rolling action, case 150 is vibratedin accordance with the rotor rotation frequency.

The oscillator just described is relatively simple and highly reliablein its operation and is capable of producing a high-amplitude sonicoutput which automatically locks in at the resonant vibration frequencyof the load being driven.

The device and method of this invention thus provide sonic means forenhancing the molding of fluid material in which the adhesion of suchmaterial to the flow defining member is minimized. In addition, thesonic action improves the structure of the material and facilitates theforming process for same.

While the device and method of this invention have been described andillustrated in detail, it is to be clearly understood that this is byWay of illustration and example only, the spirit and scope of thisinvention being limited only by the term of the following claims.

I claim:

1. A method for mold casting such as for large ingots, comprising thesteps of: V

pouring casting material into a static mold;

coupling the output of an orbiting-mass oscillator to said castingmaterial and said mold; and

driving said oscillator at a frequency such as to produce resonantelastic vibration of the resonant vibration system comprising saidcasting material and said mold, said oscillator operating toautomatically adjust the frequency and phase of its output to maintainresonant vibration of said vibration system as said fixed mass ofcasting material transforms from a liquid to a solid state.

2. The method of claim 1 wherein a dipstick is placed in said materialand said sonic oscillator is connected to said dipstick.

3. The method as recited in claim 2 wherein said resonant vibrationsystem includes a resonant bar attached to said dipstick, saidoscillator being attached to said resonant bar.

4. In a device for casting fluid material,

a mold for forming said fluid material;

an orbiting-mass sonic oscillator;

means for coupling the vibration output of said oscillator to said moldand said material, said mold and said material forming a resonantelastic vibration system; and

means for driving said oscillator at a frequency such as to causeresonant elastic vibration of said system, said oscillator being adaptedto automatically adjust its frequency and phase to maintain resonancewith changes in the impedance of said system,

whereby said resonant vibration prevents said material from adhering tosaid mold and improves the qualities of the casting.

5. In a device for the casting of fluid material,

a mold for forming said fluid material;

a dipstick partially immersed in said fluid material;

an orbiting-mass sonic oscillator;

means for connecting the vibration output of said oscillator to saiddipstick; and

means for driving said oscillator at a frequency such as to causeresonant vibration of the elastic vibrating system including saiddipstick and said material, said oscillator being adapted toautomatically adjust its frequency and phase to maintain resonance withchanges in the impedance of said system,

whereby said resonant vibration prevents said material from adhering tosaid mold and improves the qualities of the casting formed.

6. The device as recited in claim 5 wherein said means for connectingthe output of said oscillator to said dipstick includes a resonant barhaving high Q characteristics attached to said dipstick, said oscillatorbeing attached to said bar.

References Cited UNITED STATES PATENTS 2,549,179 4/ 1Delamare-Deboutteville 264-23 3,363,668 1/1968 Petit et al. 164-833,326,787 6/1967 Jacobs 26423 X 2,419,373 4/1947 Schrumn 264-832,116,367 5/1938 Smith 164260 X 2,535,596 12/1950 Peterson 164260 X3,233,012 2/1966 Bodine 26423 3,371,703 3/1968 De Wilde 16449 FOREIGNPATENTS 644,189 7/1962 Canada.

OTHER REFERENCES Ultrasonic Vibrations Refine Grain Size by D. H. Lane,I. W. Cunningham and W. A. Tiller, Metal Progress September 1959, pp.108-110.

I. SPENCER OVERHOLSER, Primary Examiner.

V. RISING, Assistant Examiner.

US. Cl. X.R.

